Shortly after a Verge report about deceptive rehab marketing on Google last September, the search giant temporarily banned ads on rehab-related searches in the U.S., which had been netting them an estimated $78 million annually. After a January Sunday Times story exposed similar practices in the U.K., focusing on a referral company called Addiction Helper, Google banned ads on rehab searches there, too.

When the new policy was enacted, The Intercept ran a story criticizing the policy for benefiting large companies with good S.E.O., noting that companies adept at gaming search can appear above unbiased sources of information like the federal government’s Substance Abuse and Mental Health Administration. Shortly after that story, SAMHSA’s helpline started showing up as the first result on most U.S.-based searches involving rehab or addiction.

Conversely, yesterday a tipster pointed out that the first result on many U.K.-based searches for drug treatment is now UK Addiction Treatment Centres, or UKAT, which owns Addiction Helper, the company profiled in the Sunday Times article. The ownership is public, and available through a Google search.

UKAT shows up first in most U.K. search results for “drug treatment” + a location, “addiction treatment” + a location, and “rehab” + a location — even when that location is Dubai, California, or other non-UK regions. None of those places are mentioned anywhere on UKAT’s homepage, and UKAT has no centers in any of those countries. It’s certainly possible UKAT has come up with a clever S.E.O. work-around to combat the traffic lost when ads were banned, but two experts we spoke with looked for evidence of common S.E.O. tricks the company might be using, and couldn’t find any.

While Google has been known to manually penalize specific sites for engaging in black-hat S.E.O., the company has never acknowledged manually boosting a specific site in organic results. But there’s some evidence they may be doing just that for addiction-related searches. Three S.E.O. experts with experience in rehab marketing told The Verge it’s likely Google has intervened to boost the SAMHSA hotline’s ranking, putting it at the top of almost every addiction-related search coming from the U.S.

Seemingly-reputable sources appear to be locked at the top of search results in other countries, too, whether as a result of manual pinning or being favored by new algorithmic priorities. Google users in India searching for many addiction-related keywords, including “12 step program” and “rehab delhi,” will see the same first result, a 2015 news article about a government-run addiction helpline. Canadian users will almost always see the top two spots dominated by a government resource page and a private rehab’s directory, which lists government-run programs at the top, though those two pages switch places depending on the search.

Whatever’s going on, the algorithm is clearly in flux: In January, even a search for “Paracelsus Recovery Switzerland,” a Zurich-based rehab, returned SAMHSA’s hotline as a first result. Today, SAMHSA isn’t even on the first page for it.

“In the U.S. and other countries, we’ve done work to refine our systems to help improve the visibility of authoritative information, such as government hotlines, in results for treatment-related searches,” a Google spokesperson told The Verge. “Our results remain dynamic and may change from query-to-query. We have not ‘locked’ any site, private or otherwise, into a specific position in these results. As with search generally, our work in this area isn’t finished, and we’ll continue to make changes to improve results for our users.”

Whether UKAT’s current reign in U.K. results is intentional or a blip, Google messing with its search results to punish bad actors in a specific industry isn’t without precedent. Starting in 2013, for instance, Google has periodically adjusted the algorithm dictating results on searches for payday lenders to de-prioritize spam and fake sites.

While the U.S. ban didn’t catch every rehab-related ad, it did catch enough of them to affect the bottom lines of many treatment centers and their affiliates. That may be the reason Google recently announced it will reinstate U.S. rehab ads, gated by a third-party vetting process. Let’s hope it’s better than whatever they’re doing right now in the U.K.